Salivary gland infections

Chapter 11

Salivary gland infections

Salivary gland infections (bacterial or viral sialadenitis) are not uncommon. The most frequently encountered infection of the salivary glands is caused by the mumps virus. However, a number of other agents, particularly bacteria, are responsible for acute sialadenitis.

The parotid glands are more commonly infected than the submandibular salivary glands and consequently most reports deal with bacterial parotitis, although the submandibular glands may be similarly affected. Infections of the accessory salivary gland can occur but are very rare (Table 11.1). Apart from mumps, the majority of salivary gland infections are seen in adults. However, there are two rather ill-defined clinical entities termed neonatal suppurative parotitis and recurrent parotitis of childhood (chronic juvenile parotitis) which are confined to the first decade of life.

Table 11.1

Classiflcation of salivary gland infections

Type of infection Gland usually affected Predisposing factor(s)
Mumps (endemic parotitis) Parotid No prior exposure to virus
Acute suppurative parotitis Parotid Severe xerostomia (e.g. Sjögren’s syndrome), localized and diffuse abnormalities of the salivary glands
Obstructive sialadenitis Submandibular Sialolith, foreign bodies, ductal strictures, mucus plugs
Suppurative and chronic recurrent parotitis of childhood Parotid Congenital or acquired abnormality of ductal system
Rare miscellaneous disorders, e.g. tuberculosis, actinomycosis and fungal infections Parotid or submandibular Systemic infection by specific agents, e.g. M. tuberculosis

As in many other infectious diseases, initiation and progression of salivary gland infections would appear to depend on the host resistance to infection and the virulence of the causative organism(s). The decrease in host resistance in the present context could be either due to general factors such as debility and dehydration or due to local factors including sialolithiasis, ductal strictures and salivary gland pathology. Factors important in salivary gland infections are shown in Figure 11.1.

Viral infections of salivary glands

Mumps (endemic parotitis)

Aetiology and epidemiology

Mumps is caused by an RNA paramyxovirus and is characterized by chronic inflammation and enlargement of salivary glands. It is frequently seen in winter and spring, and clinical or subclinical infection may occur at all ages but is most common in childhood.

The incubation period of mumps is usually 16–21 days but one month is not unusual. The saliva of patients who are incubating mumps is infectious for a few days before parotitis develops and up to two weeks after the onset of clinical symptoms. Mumps is transmitted by direct contact with saliva and by droplet spread.

Clinical presentation

There is a prodromal period of pyrexia, sore throat, furred tongue and usually a complaint of pain on chewing. Two early signs of mumps sometimes seen are the reddening of the opening of the parotid duct, and pain or tenderness on upward pressure beneath the angle of the lower jaw. As a result of infection, the salivary glands increase in size, the degree of swelling varying from little visible enlargement to gross swelling. The glands may be firmer than normal or very hard. Usually both parotid glands become enlarged at the same time but in a number of cases a single gland may be affected or there may be a delay of up to five days between the first and second glands showing evidence of infection. As a result of inflammation and oedema, the salivary flow rate is low and patients may have a non-specific stomatitis and halitosis. Pain may be acute during salivation and parotid involvement may lead to severe trismus and earache. Salivary glands other than the parotid may become enlarged and, in the case of the submandibular glands, the swelling usually occurs a few days after the parotids and may reach their peak while the parotid glands are decreasing in size. In some 10% of cases, enlargement of submandibular glands occurs without parotid involvement.

There is wide variation in the clinical course of mumps, ranging from a mild upset lasting a day or two to a severe illness with high fever lasting 10–14 days, but complete recovery is usual.

The complications of mumps are simply other manifestations of the disease less common than sialadenitis. These usually follow parotitis but may precede it or occur without salivary gland involvement. Meningoencephalitis (30%) and orchitis (25% of adult males) are common, while rare complications include oophoritis, thryroiditis, neuritis, myocarditis and nephritis.

Laboratory diagnosis

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Mar 12, 2016 | Posted by in General Dentistry | Comments Off on Salivary gland infections
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